Timer for internal-combustion engines



Aug. 26,- 1924. 1,506,666

L. L. RANDALL TIMER FOR INTERNAL COMBUSTION ENGINES Original Filed Jan. 9, 1920 4711x3511 I ii -72 ljf/anczazl Patented Aug. 26, 1924.

UNITED STATES LILLIAN L. RANDALL, OF BOSTON, MASSACHUSETTS.

TIMER FOR INTERNAL-COMBUSTION ENGINES.

Application filed January 9, 1920, Serial No. 350,318.

To all whom it may concern:

Be it known that I, LILLlAN L. RANDALL, a citizen of the United States, and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Timers for Internal-Combustion Engines, of which the following is a specification.

This invention relates to timers for internal combustion engines, and particularly to timers having a rotating contact mem ber to .establish electrical contact successively with a series of fixed contacts in circuit with the spark plugs of the engine cylinders.

Timers of this type as heretofore made, have generally been characterized by an arm carried by a rotating shaft and provided at its free end with a roller turning on an axis parallel to the shaft, which engages successively fixed contact members peripherally arranged in the path of the roller. The arm carrying the roller contact memher is pressed outwardly to insure good contact with the fixed contact members. It has been found in practice that the roller continually passing over the fixed contacts and bearing thereon with varying pressures due to varying centrifugal force of rotation, tends to wear grooves or riffles in the fixed contact members, and so to impair the electrical connections between the relatively moving contact members. The roller structure also tends not only to wear unevenly but to wear out rapidly, and is therefore undependable and costly in operation.

The present invention overcomes these objections, and produces a timer of more simple and durable construction, one in which the revolving contact member has a wiping action insuring a better electrical contact, and one in which the plane of the contacting surfaces is radially disposed with rela tion to the rotating shaft and is therefore practically uninfluenced by centrifugal force, and is uniform and certain in opera tion.

In the accompanying drawings, which illustrate the invention- Fig. 1 is a section of the timer;

Fig. 2 is an elevation viewed from the left of Fig. 1; and

Fig. 3 is a side elevation of the rotary contact member.

1 represents the casing, in the side walls of which are mounted binding posts 2, sepa- Renewed June 21, 1924.

rated from contact with the casing by bush ngs 3 of insulating material. Eachbindmg post 2 is to be connected to the spark plug of one of the cylinders of an internal combustion engine in the usual way.

Within the casing 1 is a ring 4 of insulating material such as hard fiber, hard rubber or the like; and a series of fixed contact plates 5 are set into the face of the ring opposite each binding post with their surfaces flush with the side face of the ring. Each contact plate 5 has a projection 6 extending over the inner periphery of the ring 4;, and the binding posts 2 extend through the ring and are connected to the contact plates through said projections 6.

The shaft '3 is axially disposed with relation to the casing and ring, and is rotated as usual by mechanism (not shown) connected to the crank shaft of the engine. Fastened to the end of shaft 7 is a carrier or hub 8, having a lug 9 on one side, provided with slot 10. Pivotally mounted in slot 10 by means of a pin 11 isa contact finger 12, the operative end of which rests on the ring or on the contact pieces 5 according to the angular position of the rotary parts. On the rear end of the contact finger 12 is a projection 13, and a coil spring 1a lodged in a bore 15 formed in the lug 9 presses against projection 13, thus normally urging the contact finger into close engagement with the ring 4 and contact plates 5.

To counter-balance the weight of the lug 9 and the parts carried thereby, another lug 16 is arranged diametrically opposite the lug 9.

As the shaft 7 rotates, the contact finger 12 sweeps over the smooth side face of rin l and the flush inset contact plates 5, and is held in firm wiping contact therewith by the pressure of spring 1%. The plane of the mutually engaging contact surfaces is radially disposed with relation to the rotating shaft, and consequently the contact pressure is substantially unaffected by the centrifugal force of rotation. And there is no tendency, as in timers of usual construction in which the rotating member is a contact roller pressed outwardly against peripherally arranged contact pieces, to wear grooves or riftles in the contact plates, which results in imperfect contacts. The structure is simple in construction and durable and certain in operation, and overcomes conspicuous objections to timers of this type now in general use.

I claim:

1. A timer for internal combustion engines comprising a ring of insulating material, a series of fixed contact plates set into the side face of the ring with their faces flush with the face of the ring and each having a projection extending over the inner periphery of the ring, a post connected to each of said projections and extending radially through the ring, a rotating carrier concentric with the ring having a slotted lug at one side and a counter-balancing lug at the other side, a radially disposed contact finger pivotally mounted in the slot, and a spring mounted on the carrier pressing the contact finger in an axial direction against the side face of the ring and its inset contact plates.

2. A timer for internal combustion engines comprising a ring of insulating material, a series of fixed contact plates set into the side face of the ring with their faces flush with the face of the ring and each having a projection extending over the inner periphery of the ring, a post connected to each of said projections and extending radially through the ring, a rotating carrier concentric with the ring, and a radially disposed contact finger pivotally mounted on the carrier and yieldingly pressed in an axial direction against the side face of the ring and its inset contact members.

3. A timer for internal combustion engines comprising a ring of insulating material, a series of fixed contact members set into the side face of the ring with their contact faces flush with the face of the ring, a rotating carrier concentric with the ring, said carrier having a bore extending parallel to its axis,

a pivotally mounted contact finger on said carrier, and a coil spring seated within said bore and reacting upon said linger in a direction substantially parallel to the axis of rotation of the carrier, whereby to cause the side of said finger adjacent its free end to bear against the ring and the fixed contact members.

4. A timer for internal combustion engines comprising a ring of insulating material, a series of fixed contact members set into the side face of the ring with their contact faces flush with the face of the ring, and a rotating carrier concentric with the ring having a radial slot at one side, a contact finger pivoted in the slot, the side of which near its free end bears against the ring and fixed contact members, a projection on the inner end of the contact finger, and a spring pressing against said projection and yieldingly holding the contact finger in engagement with the ring and fixed contact members.

5. A timer for internal combustion engines com n'ising a circular series of spaced and insulated contact members having their contact surfaces arranged in a radial plane, a rotatable shaft concentric with said series of contact members, a carrier fixed to said shaft, a contact lever pivot-ally supported upon said carrier for movement in a radial plane, said lever having a relatively long arm constructed and arranged for successive engagement with said contact surfaces, and an axially disposed spring engaging the short arm of said lever, and a counterbalance secured to said carrier at a point diametrically opposite said finger.

Signed by me at Boston, Massachusetts this 7 day of January 1920.

LILLIAN L. RANDALL. 

